A Thesis Submitted to the College of Graduate Studies and Research in Partial Fulfillment of the Requirements for the Degree of Master of Arts in the Department of Economics University of Saskatchewan Saskatoon

By Yajun Wang

© Copyright Yajun Wang, June, 2005. All rights reserved.

PERMISSION TO USE

In presenting this thesis in partial fulfilment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my research project.

Request for permission to copy or to make other use of material in this thesis in whole or part should be addressed to:

Head of the Department of Economics University of Saskatchewan 9 Campus Drive Saskatoon, Saskatchewan S7N 5A5

i

ABSTRACT

This thesis is an extension of a recent study into the relationship between merger size and profitability. It studies a class of Cournot oligopoly with linear cost and quadratic demand. Its focus is to analyze how a merger’s profitability is affected by its size and by the demand elasticity. Such results have not yet been reported in previous studies, perhaps due to the complexity of the equilibrium equation involved. It shows an increase in the demand elasticity also raises a merger’s profitability. Consequently, an increase in the demand elasticity reduces merged members’ critical combined per-merger market share for the merger to be profit enhancing.

Comparing with 80% minimum market share requirement for a profitable merger

in Salant, Switzer, and Reynolds (1983), a greater market share is needed when the demand function is concave (demand is relatively inelastic), while a smaller market share may still be profitable when the demand function is convex (demand is relatively elastic). In our model, mergers are generally detrimental to public interests by increasing market price and reducing output. However, the merger will be less harmful when the goods are very inelastic.

Key Words: Cournot oligopoly, demand elasticity, convexity, concavity.

ii

ACKNOWLEDGEMENTS I could not write a single page of this thesis if there were not those who continuously offering help and support to me. I would like to take this opportunity to thank all of them. Most of all, thanks for my supervisor Professor Jingang Zhao who offers me this interesting topic, where I could exercise my knowledge and wits. Without his guidance, I would have been lost in the tedious mathematical proofs and calculations. I also thank my thesis committee members, Professor Murray Fulton, Eric Howe and Nazmi Sari, for their invaluable suggestions and corrections. They challenged my wisdom and helped me to find my weakest link in Economics. I especially want to thank Professor Joel Bruneau, for his insightful discussion, always opening for questions and offering help. With his assistance in providing many cherishable intuitions for the results of my thesis, I have a clearer picture of the whole analysis. Moreover, I would also thank Professor Mobinul Huq, for his considering for students’ life and always offers time for students’ questions. In short, I want to thank all of the professors who offer me classes, and those who help me overcome the difficulties. I would also take this opportunity to thank all my friends who supported me over the past three years, especially Andrew Koeman, who helped me a lot in the analysis part in this thesis. Finally, I want to express my sincere gratitude to my beloved parents, Yonghui Wang and Xiaoqin Zhang, who always stand beside me no matter what happens. Without their love and encouragement, I would not be here now and pursue a career that I really want to do in the rest of my life.

Yajun (Francesca) Wang June 27, 2005

iii

To my parents

iv

TABLE OF CONTENTS PERMISSION TO USE----------------------------------------------------------------------------------i ABSTRACT------------------------------------------------------------------------------------------------ii ACKNOWLEDGEMENTS----------------------------------------------------------------------------iii LIST OF TABLES---------------------------------------------------------------------------------------vi LIST OF FIGURES-------------------------------------------------------------------------------------vii 1. INTRODUCTION------------------------------------------------------------------------------------1 2. PROBLEM DESCRIPTION-----------------------------------------------------------------------5 2.1 Hypothesis and Model Description-------------------------------------------------------------5 2.2 The Feasible Range of Demand Elasticity Factor “d”---------------------------------------6 2.3 The Demand Elasticity “ ε ” and the Demand Elasticity factor “ d ”-----------------------8 3. PRE-MERGER AND POST-MERGER EQUILIBRIUM-----------------------------------9 3.1 Pre-merger Equilibrium--------------------------------------------------------------------------9 3.2 Comparing with the SSR Model---------------------------------------------------------------10 3.3 Post-merger Equilibrium------------------------------------------------------------------------15 3.4 Pre-merger and Post-merger Equilibrium Comparisons------------------------------------16 4. PROFITABILITY EFFECT----------------------------------------------------------------------22 4.1 Profitability Conditions-------------------------------------------------------------------------22 4.2 Demand Elasticity, Profitable Merger Size and Profitable Combined Pre-merger Market Share-----------------------------------------------------------------------25 5. CONCLUSIONS AND FUTURE WORK-----------------------------------------------------32 APPENDIX ----------------------------------------------------------------------------------------------35 BIBLIOGRAPHY---------------------------------------------------------------------------------------52

v

LIST OF TABLES Table 4.1: The Critical Merger Sizes for Profitable Mergers Given Different Demand Elasticity Factors and Market Sizes --------------------------------------------------------------------------------------------------26 Table 4.2: The Critical Combined Pre-merger Market Shares for Profitable Mergers Given Different Demand Elasticity Factors and Market Sizes ---------------------------------------------------------------------------------------------------28 Table 4.3: The Critical Merger Sizes and the Combined Pre-merger Market Shares for Profitable Mergers Given Different Demand Elasticity ---------------------------------------------------------------------------------------------------29 Table A1: The Critical Merger Sizes and Market Shares for Profitable Mergers Given Different Demand Elasticity Factors and Market Sizes ---------------------------------------------------------------------------------------------------47

vi

LIST OF FIGURES Figure 3.1: Output Comparison with the SSR Model ------------------------------------------------------------------------------------------------12 Figure 3.2: Price Comparison with the SSR Model ------------------------------------------------------------------------------------------------12 Figure 3.3: Profit Comparison with the SSR Model -----------------------------------------------------------------------------------------------13 Figure 3.4: Comparisons between Quadratic Demand Model and the SSR Model ------------------------------------------------------------------------------------------------14 Figure 3.5: Comparisons between Pre-merger and Post-merger Equilibrium (when d>0)----------------------------------------------------------------------------------20 Figure 3.6: Comparisons between Pre-merger and Post-merger Equilibrium (when d1) firms competing as Cournot players. Firm i chooses its production q i ≥ 0 . Let Q =

∑

n q i =1 i

be the total production. As in previous studies, we assume that a unique

Cournot equilibrium always exists. Each firm faces an inverse non-linear quadratic demand function P (Q) = a − Q −

d 2 Q . 2

Even though different marginal costs provide additional incentives to a merger, in order to focus on the effect of the shape of the demand function on the profitability, as in the SSR model, we make the following assumption: each firm operates at a constant marginal and average cost of c , thus Ci (q) = cqi , where (a, c) ∈ R + + with a > c ; the demand curve is

-5-

downward sloping, hence

∂2P ∂P < 0 2; and d is a demand elasticity factor, = − d where the ∂Q ∂Q 2

demand function is concave when d>0, and convex when d max ⎨− ,− ⎬ ⎪ 2a ( n + 1 ) q ⎪ 2 ⎭⎪ ⎩⎪

Lemma 1 is derived from the following 3 restrictions: (1)The demand curve is downward sloping or

∂P = −1 − dQ < 0 ∂Q

∂P 1 = −1 − dQ < 0 , it holds automatically when d>0; when d < 0, d > − , this condition holds if the ∂Q Q Second Order Condition for profit maximization holds as shown in Proof of Proposition 1 in appendix. 2

-6-

(2) For profit maximization, the second order condition requires:

or d > −

∂ 2π i ∂q i2

0 or d0 & d

1 1 , + a ) is located in d 2d

1 1 , + a ) is located in d 2d

1 +a0, the above three conditions automatically hold. d >−

When d− =− (2) (2n + 1)q (n + 1 )q 2

d >−

1 2a

⎫ ⎧ ⎪⎪ ⎪⎪ 1 1 ⇒ d > max ⎨ − ,− ⎬ 1 ⎪ 2a (n + )q ⎪ 2 ⎭⎪ ⎩⎪

(3)

It is obvious from the above analysis, that d could be indefinitely large when it is positive. However, when d is negative, it is close to “0”. Alternatively, it could be interpreted as the convex demand function tends to be linear, and the concave demand function could be curved to any degree.

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2.3 The Demand Elasticity “ ε ” and the Demand Elasticity factor “ d ” Theoretically, the greater the demand elasticity, the more responsive the demand is to the changes in the price. The parameter “d” has direct effects on the demand elasticity. In order to explore how the merger’s profitability is affected by the demand elasticity, it is necessary for us to explore the relationship between the demand elasticity “ ε ” and the demand elasticity factor “ d ”.

Lemma 2 A smaller “ d ” implies the good is more elastic, or has a bigger absolute value of “ ε ”, assuming that P/Q remains unchanged. Solve for Q from the demand function: P(Q) = a − Q −

1 d 2 Q ⇒ Q= ( −2 + 2 1 + 2 d ( a − P ) , 2 2d

as long as d ≠ 0 3 Then, the demand elasticity: ε=

1 P ∂Q P = −(1 + 2d (a − P) )− 2 ∂P Q Q

Since ⇒ε

∂ε ∂d

3

= −(a − P )[1 + 2d (a − P)]− 2 < 0

is decreasing in d, regardless of whether “d” is positive or negative.

Keep in mind that such negative relationship between demand elasticity and the demand elasticity factor “d” assumes that small changes in d have no effects on P/Q.

We are in a

position to explore the pre-merger and post-merger equilibrium.

3

The other solution

Q =

1 (−2 − 2 1 + 2d (a − P ) 2d

could be eliminated from our analysis, because when

d>0, it is negative, and when d −

1 (n + 1 )q 0 2

All proofs of proposition 1 are in the Appendix, including the detailed formula for profits and consumer surplus.

3.2 Comparing with the SSR Model The only difference between the model we specified and the SSR model is the quadratic inverse demand function P(Q) = a − Q −

d 2 Q compared with P(Q) = a − Q in the SSR model. 2

The questions remain: Does concavity (convexity) in demand increase or decrease equilibrium price, individual supply and profit? What about the effect on the consumer surplus and welfare? Proposition 2 sets about answering these questions. To simplify the analysis further, we

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compare these two models in per-merger equilibrium.4 Before presenting this proposition, we first introduce some results from the SSR model: q iL0 =

(a − c )2 a−c , π iL0 = n +1 (n + 1) 2

and PL0 =

a + cn , n +1

where q iL0 , π iL0 are each producer’s output and profit respectively, and PL0 is the market price in the pre-merger equilibrium in the linear demand model.

Proposition 2 Let qi0 & qiL0 , P 0 & PL0 , π i0 & π iL0 be the Cournot pre-merger equilibrium individual firm’s outputs, market price and individual firm’s profit for quadratic and linear demand models respectively. Then: (1) q i0 < q iL0 , if d>0 0 q i0 > q iL , if d PL0 , if d>0 P 0 < PL0 , if d π iL0 , if − 4

(n + 1) 2 (n + 2) 3 ω

(n + 1) 2 (n + 2) 3 ω

π i0 = π iL0 , if d = −4

or d > 0

PL0 , if d > 0 -0.04

P 0 < PL0 , if d < 0

-0.02

0

0.02 -0.1

Note: the Vertical axis is the price difference. -0.2

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0.04

d

Each individual firm’s profit difference between these two models would be: 0 π i0 − π iL =

1 (62430120 d + 1030301) 10201 + 1224000 d − 12548454120d − 104060401 + 1910174400 00d 2 5412691404 00 d2

Then π i0 < π iL0 , if d < − π i0 > π iL0 , if −

10201 or d > 0 15918120

10201 0 be the Cournot pre-merger equilibrium consumer surplus and welfare when the demand function is concave, and let CSd0< 0 and Wd0< 0 be the consumer surplus and welfare when the demand function is convex, and let CS L0 and WL0 be the consumer surplus and welfare in the SSR model, then:

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(1.1) CS d0>0 < CS L0 < CS d00 < WL0 < Wd0< 0

Figure 3.4 Comparisons between Quadratic Demand Model and the SSR Model P a P1 is the equilibrium price when d>0 PL is the equilibrium price in SSR model P2 is the equilibrium price when d 0) 2

a P = a−Q

In Figure 3.4 Point A (PL, QL) is the equilibrium in the SSR model. Point B (P1, Q1) is the equilibrium when the demand function is concave. Point C (P2, Q2) is the equilibrium when the demand function is convex.

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The comparison between our quadratic non-linear model and the SSR model can be illustrated in Figure 3.4. Even though it is ambiguous to rank the industry profits among these three cases, it is quite obvious from this graph that consumers will gain due to increased output and reduced price in the market when d0, compared with the linear demand model. As for the welfare effect, when d0, welfare is smaller compared with the SSR model. However, it is not clear which demand curve is the optimal one to achieve social efficiency, since the deadweight loss varies with both the output level and the demand elasticity. A few words must be added in linking the results presented to the theoretical discussion of demand elasticity and suppliers’ output production decisions. In a quantity-setting game, when the product is more elastic (d becomes smaller), producers are inclined to produce more, because a huge output expansion could only be followed by a marginal decrease in output price. As for consumers, they definitely will gain because of the lower price and higher outputs. And social welfare will increase as well, compared with a product that is less elastic. All of the previous discussions focus on the pre-merger equilibrium. There is still the question of how the merger has an impact on this equilibrium. The next section presents the post-merger equilibrium.

3.3 Post-merger Equilibrium Before analyzing the output, price and profitability effect of the merger, it is necessary to obtain the post-merger equilibrium. The below proposition shows the equilibrium insiders’

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output and profit, the outsider’s output and profit, and the output of the whole industry, market price, as well as consumer surplus and producer surplus after the merger.

Proposition 3 Let the post-merger equilibrium individual firm’s output and profit be q i* , π i* . * be the combined merged parties’ profits, and let the total industry output, price, profit Let π M

and consumer surplus be Q* , P* , π * and CS * respectively. Then q i* =

1 ⎡− (n - m + 2) + (n − m + 2) 2 + 2d (a − c)(n − m + 1)(n − m + 3) ⎤ ⎥⎦ d (n − m + 1)(n − m + 3) ⎢⎣

Q* =

1 ⎡− (n - m + 2) + (n − m + 2) 2 + 2d (a − c)(n − m + 1)(n − m + 3) ⎤ ⎥⎦ d (n − m + 3) ⎢⎣

P* =

d (n − m + 3)(c(n − m + 1) + 2a ) + (n − m + 2) − (n − m + 2) 2 + 2d (a − c)(n − m + 1)(n − m + 3) d (n − m + 3) 2

π i* = ( P* − c)qi* * πM = ( P* − c) qi*

π * = ( P* − c)Q*

CS

*

=

∫

Q*

0

d 2⎞ ⎛ * * ⎜ a − Q − Q ⎟ dQ − P × Q 2 ⎝ ⎠

Notice that d >

−2

{2(n − m + 1) + 1}q i*

, from S.O.C.

3.4 Pre-merger and Post-merger Equilibrium Comparisons The purpose of this subsection is to demonstrate the impact of merging on the individual firm’s output decision, both for insiders and outsiders, as well as the industry output and price. Furthermore, it analyzes if the demand elasticity factor “d” has an impact on the equilibrium. It gives us a clearer picture of how the market reacts in response to the merger, and offers a foundation for further analysis on a coalition’s profitability.

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In order to derive the impact of “d” on total output change in the market, we impose the following restriction on the demand function. Assumption 1 (A1)5:

∂P ∂ 2 P + q i < 0 6 for all 0 ≤ qi ≤ Q , as long as P>0 2 ∂Q ∂Q

There are two different interpretations for this assumption in the literature: ♦

Hahn (1962) first made this assumption, and he interpreted it as: at all possible outputs, the marginal revenue of any one producer with a given output is a diminishing function of the total output of his rivals.

♦

Ruffin (1971) shows the reasonableness of this assumption, and offers an alternative interpretation, which is: “at all possible outputs, the marginal revenue function facing any firm is steeper than the demand function.”

♦

Levin (1990) mentions A1 as an important extension of the example in the SSR which assumes that

∂2P ∂Q 2

= 0.

The next proposition compares the pre-merger and post-merger equilibrium. Proposition 4 Let the pre-merger equilibrium individual firm’s output, the total industry output and price be qi0 , Q 0 , and P 0 respectively. Let the post-merger equilibrium individual firm’s output, the total industry output and price be q i* , Q* and P* respectively. Then q i* − mq i0 will be the total insiders’ output change, qi* − qi0 will be each outsider firm’s output change, Q * − Q 0 will be the total industry output change, and P * − P 0 will be the market price 5

Levin (1990) uses this assumption to derive the total output impact of the merger in a general model, which shows that the total output in the industry will expand (contract) if the merger expands (contracts) its output level.

6

∂P ∂ 2 P q i = − 1 − d (Q + q ) < 0 + ∂Q ∂Q 2

This condition automatically holds when d>0, and when d is negative, 0 > d >

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−1 q ( n + 1)

.

difference. Let q iL* , Q L* and PL* be the Cournot post-merger equilibrium coalition’s combined outputs (or each outsider’s output), total market outputs, and market price in the SSR model respectively. Then, (1) The Merger leads to a contraction of the insiders’ total output relative to the pre-merger level. q i* < mq i0 , as long as d ≠ 0

Remark: lim q i* = mq i0 d →∞

* lim q i* = q iL

d →0

(2) Each outsider will expand their output in response to the merging. q i* > q i0 , as long as d ≠ 0

Remark: lim q i* = q i0 d →∞

* lim q i* = q iL

d →0

(3) The Merger leads to the contraction of the total output in the market relative to the pre-merger level.7 Q * < Q 0 , as long as d ≠ 0

Where Q * = Q M* + Q F* and Q 0 = Q M0 + Q F0 , for all i (i ∈ M ) & j ( j ∈ F ) . Where Q M0 is the insiders’ total outputs before the merger. Where QF0 is the outsiders’ total outputs before the merger. Where Q M* is the insiders’ total outputs after the merger. Where QF* is the outsiders’ total outputs after the merger. Remark: lim Q * = Q 0 d →∞

7

Levin (1990) proved proposition 4, (3) by assuming proposition 4, (1) for a general case.

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lim Q * = Q L*

d →0

As for the price effect, it is obvious that the contraction of the output supply will always push up the price. The related proofs for proposition 4 are in the appendix. Given the pre-merger output level of the outsiders, the insiders tend to reduce their post-merger outputs. On the other hand, the outsiders will expand their outputs in response to a higher price, which is one of the main effects of the merging. They become the free riders in the industry, followed by further output reduction of insiders. After all of these adjustments have taken place, coalition members may be unprofitable compared with the pre-merger level; since the gain from a higher price could not outweigh the loss from lower output, their share of the pie decreased. Not surprisingly, in order to overcome outsiders’ output expansion effect, a merger needs to have at least 80% market share for it to be profitable in the SSR model. Since in our model, the demand elasticity factor d is a crucial factor for its effect on the profitability conditions, I would like to include the graphs for positive d and negative d respectively, where the demand function is concave when d>0, and convex when d CS * , due to increase in price and decrease in output in the market. (2.3) W 0 > W * , because of the increase in the deadweight loss after the merger.

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Figure 3.5 Comparisons between Pre-merger and Post-merger Equilibrium (when d>0) P

(−

1 1 , + a) d 2d

a

P = a−Q −

d2 2 Q (d 2 > d ) 2

P = a−Q−

P*

CS

d 2 Q 2

P0 P = a−Q

PS DWL

c Q Q*

Q0

a

In Figure 3.5 and 3.6, the convexity or concavity of the demand function does not change the main outcomes of merging. However, when the demand elasticity factor is very large, which implies the good is perfectly inelastic (it could be represented by the inner light demand function in Figure 3.5, where d 2 > d ), it will be difficult for the coalition to reduce the output level by a large enough factor to increase the market price. In this case, the merger will be less harmful.

The results from proposition 4 and corollary 2 are consistent with merger theory. The aim of merging is to increase profit by reducing the competition. An industry will be less competitive when there are fewer firms. The Cournot oligopoly players in this model will restrict the amount of output they produce in order to push up the price, and this is detrimental to the public interests.

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Figure 3.6 Comparisons between Pre-merger and Post-merger Equilibrium (when d −

1 , 2a

which makes d range from a very small negative number to zero when the demand function is convex. As discussed in chapter 4, we would predict that when d is a very large negative number, or alternatively, the demand is perfectly elastic, much less market share is required for a profitable merger even with constant return to scale, which would be interesting. We could consider an alternative model, such as P(Q) = a − Q −

d Q 2 . This model would 1000

allow us to go further in our analysis for the convex demand function case, because it relaxes the restriction to be d > − ♦

250 . a

In our analysis, the merger’s output is always decreasing compared with their pre-merger level. However, the result could be ambiguous when the merger experiences economies of scale after they form a coalition, which is always true in real life. Firms will expand their output level when the cost is reduced. Thus, we could introduce a scale economy factor into our cost function. Our model could be further expanded when the cost function is asymmetric.

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♦

Finally, applying this model in a heterogeneous goods market would serve as a more challenging analysis, but also one that is of considerable economic interest.

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Appendix

Proof of Proposition 1: For each individual firm i to maximize its profit: π i = (a − Q − ⎡

d 2 Q )q i − cq i , where Q = 2

or π i = ⎢a − ( ⎢⎣

∑q

k

k ≠i

+ qi ) −

n

∑q = ∑q k

k =1

k

+ qi

k ≠i

⎤ d ( q k + q i）2 ⎥ q i − cq i 2 k ≠i ⎥⎦

∑

The first order condition is: ∂π i d = a − 2q i − q k − ( q k + q i ) 2 − d ( q k + q i )q i − c = 0 , ∂q i 2 k ≠i k ≠i k ≠i

∑

or a − qi − Q −

∑

∑

d 2 Q − dQqi − c = 0 2

(A3.1) (A3.1a)

In a symmetric Nash equilibrium, the output of each firm in the industry will be identical, so that, for all i (i ∈ M ) and j ( j ∉ M ) , q i = q j = q 0 , or a − q 0 − nq 0 −

2 d 2 02 n q − dnq 0 − c = 0 2

(A3.1b)

Solving for q 0 in equation A3.1b, we get proposition 1.

Check the second order condition: ⇒0>d >

−2 (2n + 1)q 0

∂ 2π i ∂q i 2

= −2 − 2d ( ∑ q k + q i ) − dq i < 0 k ≠i

, or d > 0 .

Thus, in pre-merger equilibrium, For each outsider and insider, the individual profit is: π i0 = ( P 0 − c)q i0

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=2

[d (a − c)(n + 2) + (n + 1)]

[

(n + 1) 2 + 2nd (a − c)(n + 2) − d (n + 2)(2n + 1)(a − c ) + (n + 1) 2

]

d (n + 2) n 2

3

For the merged firm M, the combined pre-merger profit is: 0 πM = m( P 0 − c)q i0

[d (a − c)(n + 2) + (n + 1)]

= 2m

[

(n + 1) 2 + 2nd (a − c)(n + 2) − d (n + 2)(2n + 1)(a − c) + (n + 1) 2

]

d ( n + 2) n 2

3

The total producer surplus will be: π 0 = ( P 0 − c)Q 0 =2

[d (a − c)(n + 2) + (n + 1)]

[

(n + 1) 2 + 2nd (a − c)(n + 2) − d (n + 2)(2n + 1)(a − c) + (n + 1) 2 d (n + 2) 2

]

3

The total consumer surplus will be: CS 0 =

Q0

∫0

(a − Q −

d 2 Q ) dQ − P 0 × Q 0 2

4dn(n + 2)(a − c)(n + 1 − (n + 1) 2 + 2nd (a − c)(n + 2) ) + (n − 2)⎛⎜ n + 1 − (n + 1) 2 + 2nd (a − c)(n + 2) ⎞⎟ ⎝ ⎠ =− 2 3 6d (n + 2)

2

Q.E.D.

Proof of Proposition 2 (1) The difference between the Cournot pre-merger equilibrium individual firm’s output in the

quadratic demand model and the linear demand model is: 0 q i0 − q iL =

− (n + 1) 2 + (n + 1) 2 + 2ndω (n + 2) (n + 1) − ndω (n + 2) dn(n + 2)(n + 1)

Let the numerator − (n + 1) 2 + (n + 1) 2 + 2ndω (n + 2) (n + 1) − ndω (n + 2) = ρ1 Then lim ρ1 = 0 d →0

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(A3.2.1)

{

}

1 − ∂ρ 1 1 = ( n + 1) 2 + 2ndω (n + 2) 2 × 2nω ( n + 2)( n + 1) − nω ( n + 2) ∂d 2

1 ⎡ ⎤ − = nω (n + 2) ⎢⎢ (n + 1) 2 + 2ndω (n + 2) 2 (n + 1) − 1⎥⎥ ⎢⎣ ⎥⎦

{

{

}

}

1 − ∂ρ 2 When d > 0, (n + 1) + 2ndω (n + 2) 2 (n + 1) < 1 ⇒ 1 < 0 ∂d lim ρ1 = 0 d →0

⇒ ρ1 < 0 , when d > 0 .

Since the denominator in equation A3.2.1 is positive when d>0 ⇒

0 q i0 < q iL , when d > 0 .

We could prove when d < 0, ρ 1 > 0 , then q i0 > q iL0 by using the same method. Thus, compared with the production in the linear demand model, individual firm produces more output when the demand function is convex, and fewer outputs when the demand function is concave. Q.E.D.

(2) The difference between the Cournot pre-merger equilibrium market price in the quadratic

demand model and the linear demand model is: P 0 − PL0 =

(n + 1) 2 − (n + 1) 2 + 2ndω (n + 2) (n + 1) + ndω (n + 2)

d (n + 2) 2 (n + 1)

(A3.2.2)

Since (n + 1) 2 − (n + 1) 2 + 2ndω (n + 2) (n + 1) + ndω (n + 2) = − ρ1 , we could get the opposite result to (1). Compared with the market price in the linear demand model, market price is lower when the demand function is convex and higher when the demand function is concave. Q.E.D.

(3) The difference between the Cournot pre-merger equilibrium individual firm’s profit in the

quadratic demand model and the linear demand model is:

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π i0 − π iL0 =

(

)

2 dω (n + 2)(n + 1)2 + (n + 1)3 (n + 1)2 + 2ndω (n + 2) − 2dω (n + 2)(2n + 1)(n + 1)2 − 2(n + 1)4 − d 2ω 2n(n + 2)3 d 2 (n + 2)3 n(n + 1)2

(A3.2.3)

(

2 dω (n + 2)(n + 1) 2 + (n + 1) 3

Let the numerator:

) (n + 1)

2

+ 2ndω (n + 2)

− 2dω (n + 2)(2n + 1)(n + 1) 2 − 2(n + 1) 4 − d 2ω 2 n(n + 2) 3 = ρ 2

Solve for ρ 2 > 0 We get − 4

(n + 1) 2 (n + 2) 3 ω

0

0 ⇒ π i0 > π iL0

(n + 1) 2

ω ( n + 2)

3

(n + 1) 2 (n + 2) 3 ω

, we could get ρ 2 < 0 ⇒ π i0 < π iL0 , we could get ρ 2 = 0 ⇒ π i0 = π iL0

A merger generally earns more profit when the demand function is linear, except when the demand elasticity factor ranges from − 4

(n + 1) 2

ω (n + 2) 3

Q.E.D.

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to 0 .

Proof of Proposition 3: After a merger, for each firm i to maximize its profit: ⎡

π i = ⎢a − ( ∑ q k + q i ) − ⎣

k ≠i

⎤ d ( ∑ q k + q i）2 ⎥ q i − cq i 2 k ≠i ⎦

The first order condition is: ∂π i d = a − 2q i − q k − ( q k + q i ) 2 − d ( q k + q i )q i − c = 0 2 k ≠i ∂q i k ≠i k ≠i

∑

∑

∑

(A3.3)

Specifically, for the merged firm M to maximize its profit: ⎡

π M = ⎢a − ( ⎢⎣

∑q

k

+ qM ) −

k ≠M

⎤ d ( q k + q M）2 ⎥ q M − cq M 2 k ≠M ⎥⎦

∑

The first order condition is: ∂π M d = a − 2q M − qk − ( qk + qM ) 2 − d ( q k + q M )q M − c = 0 ∂q M 2 k ≠M k ≠M k ≠M

∑

∑

∑

(A3.3a)

There are (n − m + 1) firms in the market after merger, then: for all j ( j ∉ M ) and M (i ∈ M ) , q j = q M = q * Q = (n − m + 1)q *

or a − q * − Q −

d 2 Q − dQq * − c = 0 2

or a − q * − (n − m + 1)q * −

2 d (n − m + 1) 2 q * − d (n − m + 1)q * − c = 0 2

Solve for q * in equation A3.3b leads to Proposition 3.

Check the second order condition: ∂ 2π M ∂q M 2

= −2 − 2 d (

⇒0>d >

∑q

k

+ q M ) − dq M < 0

k ≠M

−2

{2(n − m + 1) + 1}q *

To simplify the notations, let n * = n − m + 1 Thus, for each outsider and the coalition, the profit will be: * π *j = π M = ( P * − c)q *

- 39 -

(A3.3b)

[d (a − c)(n

=2

*

]

[

+ 2) + (n * + 1) (n * + 1) 2 + 2d (a − c)n * (n * + 2) − d (n * + 2)(2n * + 1)(a − c ) + (n * + 1) 2 d ( n + 2) n 2

*

3

]

*

The producer surplus after merger will be: π * = ( P * − c)Q * =2

[d (a − c)(n

*

]

[

+ 2) + (n * + 1) (n * + 1) 2 + 2d (a − c)n * (n * + 2) − d (n * + 2)(2n * + 1)(a − c) + (n * + 1) 2 d ( n + 2) 2

*

]

3

The consumer surplus will be: d Q* ⎛ 1 2 d 3 ⎞ CS * = ∫0 ⎜ a − Q − Q 2 ⎟dQ − P * × Q* = aQ* − Q* − Q* − P * × Q* 2 2 6 ⎝ ⎠ ⎛ ⎞ 4dn* (n* + 2)(a − c)(n* + 1 − (n* + 1) 2 + 2d ( a − c)n* (n* + 2) ) + (n* − 2)⎜ n* + 1 − ( n* + 1) 2 + 2d (a − c) n* ( n* + 2) ⎟ ⎝ ⎠ =− 6 d 2 ( n* + 2) 3

Q.E.D.

Proof of Proposition 4 (When d>0) To simplify the notations, Let ω = a − c X = n +1 Y = n−m+2

(1) The difference between a coalition’s post-merger output and combined pre-merger output is: ⎛ − Y + Y 2 + 2dω (Y 2 − 1) ⎞( X 2 − 1) − m⎛ − X + X 2 + 2dω ( X 2 − 1) ⎞(Y 2 − 1) ⎜ ⎟ ⎜ ⎟ ⎝ ⎠ ⎝ ⎠ q − mq = d ( X 2 − 1)(Y 2 − 1) *

0

(A3.4.1)

Let the numerator ⎛⎜ − Y + Y 2 + 2dω (Y 2 − 1) ⎞⎟( X 2 − 1) − m⎛⎜ − X + X 2 + 2dω ( X 2 − 1) ⎞⎟(Y 2 − 1) = ϕ1 ⎝

⎠

⎝

Then lim ϕ1 = 0 d →0

- 40 -

⎠

2

{

}

1 − ∂ϕ1 1 2 m 2 2 = Y + 2dω (Y − 1) 2 × 2ω (Y 2 − 1)( X 2 − 1) − X + 2dω ( X 2 − 1) 2 ∂d 2

{

⎡ ⎢ 2 2 = ( X − 1)(Y − 1)ω ⎢ Y 2 + 2dω (Y 2 − 1) ⎢ ⎣

{

{

}

}

−

1 2

}

⎧⎪ X 2 + 2dω ( X 2 − 1) ⎫⎪ −⎨ ⎬ ⎪⎩ ⎪⎭ m2

−

1 2

−

1 2

× 2ω ( X 2 − 1)(Y 2 − 1)

⎤ ⎥ ⎥ ⎥ ⎦

(A3.4.1a)

⎧⎪ X 2 + 2dω ( X 2 − 1) ⎫⎪ ⎬ from equation A3.4.1a ⎪⎩ ⎪⎭ m2

Let ϕ11 = Y 2 + 2dω (Y 2 − 1) − ⎨ = (Y 2 −

⎧⎪ m 2 (Y 2 − 1) − ( X 2 − 1) ⎪⎫ ) 2 d ω + ⎨ ⎬ ⎪⎩ ⎪⎭ m2 m2 X2

Since: ♦

Y2 −

X2 m

2

= (Y +

X X X ⎡ n + 1⎤ )(Y − ) = (Y + ) ⎢(n − m + 2) − m m m ⎣ m ⎥⎦

= (Y +

X ⎛ (m − 1)(n − m + 1) ⎞ )⎜ ⎟>0 m ⎝ m ⎠

{

♦

}{

}

m 2 (Y 2 − 1) − ( X 2 − 1) = m 2 (n − m + 2) 2 − 1 − (n + 1) 2 − 1

= m 2 n 2 − 2m 3 n + 4m 2 n + m 4 − 4m 3 + 3m 2 − n 2 − 2n

{

}

= (m − 1) (m − 1)(m − n) 2 + 2m(n − m) + 2n(n − m + 1) > 0 ⇒ ϕ11 > 0 , or Y 2 + 2dω (Y 2 − 1) >

Since when f ( x) = x ⎡ ⎢ ⇒ ⎢ Y 2 + 2dω (Y 2 − 1) ⎢ ⎣

{

−

}

−

1 2

1 2

X 2 + 2dω ( X 2 − 1) m2

, f ( x) ↑ with x ↓

⎧⎪ X 2 + 2dω ( X 2 − 1) ⎫⎪ −⎨ ⎬ ⎪⎩ ⎪⎭ m2

−

1 2

⎤ ∂ϕ1 ⎥ X 2 + 2dω ( X 2 − 1)

−

1 2

( X 2 − 1)(Y 2 − 1)ω > 0

⇒

∂ϕ 2 >0 ∂d

⎫ ⎧ ∂ϕ 2 ⎪ ∂d > 0 ⎪ ⎬ ⇒ When d > 0, ϕ 2 > 0 , ⎨ ⎪ lim ϕ1 = 0⎪ ⎭ ⎩d →.0

Since the denominator for equation A3.4.2 is positive, ⇒

q* > q 0

Each outsider will expand individual output following the merger. Q.E.D.

(3) The total output change in the market is: − (Y + 1)⎧⎨− X + X 2 + 2dω ( X 2 − 1) ⎫⎬ + ( X + 1)⎧⎨− Y + Y 2 + 2dω (Y 2 − 1) ⎫⎬ ⎩ ⎭ ⎩ ⎭ Q −Q = d ( X + 1)(Y + 1) *

0

(A3.4.3)

The unique Cournot-Nash Equilibrium (CNE) is characterized by the F.O.C conditions for profit maximization of n firms: P(Q) +

∂P(Q) qi − c = 0 ∂Q

(A3.4.3a)

- 42 -

∂P (Q 0 )

P (Q 0 ) +

∂Q 0

q i (Q 0 ) − c = 0

q i (Q * ) > q i (Q 0 ) ∂P(Q 0 )

⇒ P (Q 0 ) +

∂P (Q 0 ) ∂Q

0

q i (Q * ) − c < 0

0 ⎩ 2 ⎭

(A3.4.4)

Q.E.D.

Proof of Proposition 4 (When d (Y 2 −

m

=

ω

(1 −

a

2

1 m

)−

)+ 2

ω ⎧⎪ m 2 (Y 2 − 1) − ( X 2 − 1) ⎫⎪ ⎨ a ⎪⎩

m

2

1 ⎬ , since d > − 2a ⎪⎭

c 2 X2 (Y − 2 ) > 0 a m

{

}

⎧⎪ X 2 + 2dω ( X 2 − 1) ⎪⎫ ⇒ Y 2 + 2dω (Y 2 − 1) − ⎨ ⎬>0 ⎪⎩ ⎪⎭ m2

Since for function f ( x) = x ⎡ ⎢ ⇒ ⎢ Y 2 + 2dω (Y 2 − 1) ⎢ ⎣

{

}

−

1 2

−

1 2

, f ( x) ↑ with x ↓

⎧⎪ X 2 + 2dω ( X 2 − 1) ⎫⎪ −⎨ ⎬ ⎪⎩ ⎪⎭ m2

−

1 2

⎤ ∂δ 1 ⎥ 0.

Q.E.D.

(2) The individual outsider’s output change is given by: ⎛ − Y + Y 2 + 2dω (Y 2 − 1) ⎞( X 2 − 1) − ⎛ − X + X 2 + 2dω ( X 2 − 1) ⎞(Y 2 − 1) ⎟ ⎜ ⎟ ⎜ ⎠ ⎝ ⎠ ⎝ q −q = 2 2 d ( X − 1)(Y − 1) *

0

(A3.4.2)

Let the numerator ⎛⎜ − Y + Y 2 + 2dω (Y 2 − 1) ⎞⎟( X 2 − 1) − ⎛⎜ − X + X 2 + 2dω ( X 2 − 1) ⎞⎟(Y 2 − 1) = δ 2 ⎠

⎝

⎠

⎝

Then lim δ 2 = 0 d →0

⎡ ∂δ 2 = ( X 2 − 1)(Y 2 − 1)ω ⎢ Y 2 + 2dω (Y 2 − 1) ∂d ⎢⎣

{

{

} − {X

}{

}

−

1 2

2

}

+ 2dω ( X 2 − 1)

Since Y 2 + 2dω (Y 2 − 1) − X 2 + 2dω ( X 2 − 1)

- 44 -

−

1 2

⎤ ⎥ ⎥⎦

= (Y 2 − X 2 )(1 + 2dω )

From lemma 1, we know 2d > −

1 a

⇒ (1 + 2dω ) > (1 −

ω a

)=

c >0 a

Since (Y 2 − X 2 ) < 0

{

} {

}

⇒ Y 2 + 2dω (Y 2 − 1) < X 2 + 2dω ( X 2 − 1)

Since for function f ( x) = x

{

}

⇒ Y 2 + 2dω (Y 2 − 1)

−

1 2

−

1 2

, f ( x) ↓ with x ↑

{

}

> X 2 + 2dω ( X 2 − 1)

−

1 2

⇒

∂δ 2 >0 ∂d

⎫ ⎧ ∂δ 2 ⎪ ∂d > 0 ⎪ ⎬ ⇒ When d < 0, δ 2 < 0 ⎨ ⎪ lim δ 2 = 0⎪ ⎭ ⎩d →.0

Since the denominator of equation A3.4.2 is negative, ⇒

q * > q 0 , which is the same result as when d>0.

Q.E.D.

(3) The total output change in the market is: − (Y + 1)⎧⎨− X + X 2 + 2dω ( X 2 − 1) ⎫⎬ + ( X + 1)⎧⎨− Y + Y 2 + 2dω (Y 2 − 1) ⎫⎬ ⎩ ⎭ ⎩ ⎭ Q −Q = d ( X + 1)(Y + 1) *

0

Proof: P(Q) + P (Q 0 ) +

∂P (Q) qi − c = 0 ∂Q

∂P (Q 0 ) ∂Q

0

q i (Q ) > q i (Q 0 ) *

∂P(Q 0 ) ∂Q 0

(3.4.3) (3.4.3a)

q i (Q 0 ) − c = 0 ⇒ P (Q 0 ) +

∂P (Q 0 ) ∂Q 0

q i (Q * ) − c < 0

Q * , which is the same result as when d > 0 .

Q.E.D.

(4) Price will rise after merging. ⎧ d ⎫ P * − P 0 = (Q 0 − Q * )⎨1 + (Q * + Q 0 )⎬ ⎩ 2 ⎭

Since

1 1 d * Q* − Q 0 , because of second order conditions: (Q + Q 0 ) > − 2 {2(n − m + 1) + 1}q i* (2n + 1)q i0

♦

d>

♦

d>

−2

(2n + 1)q i0

, from proposition 1.

−2 , from proposition 3 {2(n − m + 1) + 1}qi*

1 1 2n − m + 2 ⎧ d ⎫ (n − m + 1)q i* − ⇒ ⎨1 + (Q * + Q 0 )⎬ > 1 − nq i0 = >0 * 0 (2n + 1)(2n − 2m + 3) (2n + 1)q i {2(n − m + 1) + 1}q i ⎩ 2 ⎭

Q * < Q 0 , from Proposition 4.(3)

⇒ P* − P 0 > 0 Q.E.D.

- 46 -

Table A1: The Critical Merger Sizes and Market Shares for Profitable Mergers Given Different Demand Elasticity Factors and Market Sizes10

Where: ♦

n is the market size

♦ m values are all the critical merger sizes to allow the insiders’ combined pre-merger * to be equal. profit π M0 and post-merger profit π M

♦

m * is the feasible critical merger size for a profitable merger.

♦ m*/n is the least insiders’ combined pre-merger market share for a profitable merger. d

n

-0.005

3 5 6 7 8 10 20 30 40 50

10

When d ≠ 0, * 0 −πM =2 πM

m values m1 = 2.36655, m 2 = 1.0, m 3 = 7.91203 − 5.20187 i, m 4 = 7.91203 + 5.20187 i m1 = 3.89158, m 2 = 1.0, m3 = 10.415 − 6.89765i, m 4 = 10.416 + 6.89765i m1 = 4.68648, m 2 = 1.0, m3 = 11.6322 − 7.66484i, m 4 = 116.6322 + 7.66484i m1 = 5.49654, m2 = 1.0, m3 = 12.83 − 8.3909i, m4 = 12.83 + 8.3909i m1 = 6.31887, m 2 = 1.0, m3 = 14.0124 − 9.08225i, m 4 = 14.0124 + 9.08225i m1 = 7.9925, m2 = 1.0, m3 = 16.3392 − 0.3793i, m4 = 16.3392 + 10.3793i m1 = 16.7003, m 2 = 1.0, m 3 = 27.5097 − 15.7726i, m 4 = 27.5097 + 15.7726i m1 = 25.7026, m 2 = 1.0, m 3 = 38.2725 − 20.1252i, m 4 = 38.2725 + 20.1252i m1 = 34.8596, m 2 = 1.0, m 3 = 48.8282 − 23.8812i, m 4 = 48.8282 + 23.8812i m1 = 44 .1159 , m 2 = 1.0, m 3 = 59 .2577 − 27 .2336 i , m 4 = 59 .2577 + 27 .2336 i

{dω (Y + 1)(−2Y +

β + 1) + Y ( −Y + β )

d 2 (Y + 1) 2 (Y 2 − 1)

* 0 When d=0, π M −π M =

(a − c) 2 ( n − m + 2) 2

−m

} − 2m {dω ( X + 1)(−2 X +

m*

m*/n

2.36655

78.89%

3.89158

77.83%

4.68648

78.11%

5.49654

78.52%

6.31887

78.99%

7.9925

79.93%

16.7003

83.50%

25.7026

85.68%

34.8596

87.15%

44.1159

88.23%

α + 1) + X ( − X + α )

d 2 ( X + 1) 2 ( X 2 − 1)

(a − c) 2 (n + 1) 2

- 47 -

}

60 70 80 90 100

d

n

0

3 5 6 7 8 10 20 30 40 50 60 70 80 90 100

d

n

0.05

3 5 6 7 8

m1 = 53.4431, m 2 = 1.0, m 3 = 69.6026 − 30.2885i, m 4 = 69.6026 + 30.2885i m1 = 62.8241, m 2 = 1.0, m3 = 79.8873 − 33.1119i, m 4 = 79.8873 + 33.1119i m1 = 72.2477, m 2 = 1.0, m3 = 90.1271 − 35.7483i, m5 = 90.1271 + 35.7483i m1 = 81.7062, m 2 = 1.0, m3 = 100.332 − 38.2297i, m 4 = 100.332 + 38.2297i m1 = 91 .1939 , m 2 = 1 .0, m 3 = 110 .51 − 40 .5798 i , m 4 = 110 .51 + 40 .5798 i

m values m1 = 2.43845, m 2 = 1.0, m3 = 6.56155 m1 = 4.0, m 2 = 1.0, m3 = 9 m1 = 4.80742, m 2 = 1.0, m3 = 10.1926 m1 = 5.62772, m 2 = 1.0, m3 = 11.3723 m1 = 6.45862, m 2 = 1.0, m3 = 12.5414 m1 = 8.1459, m 2 = 0.999999, m3 = 14.8541 m1 = 16.8902, m 2 = 0.999999, m3 = 16.8902 m1 = 25.9098, m 2 = 0.999999, m3 = 37.0902 m1 = 35.0774, m 2 = 1.0, m3 = 47.9226 m1 = 44.3411, m2 = 1.0, m3 = 58.6589 m1 = 53.6738, m2 = 1.0, m3 = 69.3262

m1 = 63.059, m2 = 1.0, m3 = 79.941

m1 = 72.4861, m 2 = 1.0, m3 = 90.5139 m1 = 81.9475, m2 = 1.0, m3 = 101.052

m1 = 91.4377, m 2 = 0.999999, m3 = 111.562

m values m1 = 2.53012, m 2 = 0.999998, m3 = 6.54682 − 3.27804i, m 4 = 6.54682 + 3.27804i m1 = 4.13216 , m 2 = 0.999999 , m 3 = 8 .73164 − 4 .2549 i , m 4 = 8.73164 + 4 .2549 i m1 = 4.95299, m 2 = 1.0, m 3 = 9.80577 − 4.68696i, m 4 = 9.80577 + 4.68696i m1 = 5.78412 , m 2 = 1.0, m 3 = 10.8712 − 5.09188 i, m 4 = 10.8712 + 5.09188 i m1 = 6.62399 , m 2 = 1.0, m 3 = 11.9295 − 5.47436 i, m 4 = 11.9295 + 5.47436 i

- 48 -

53.4431

89.07%

62.8241

89.75%

72.2477

90.31%

81.7062

90.785%

91.1939

91.19%

m*

m*/n

2.43845 4 4.80742 5.62772 6.45862 8.1459 16.8902 25.9098 35.0774 44.3411 53.6738 63.059 72.4861 81.9475 91.4377

81.28% 80% 80.12% 80.40% 80.73% 81.46% 84.45% 86.37% 87.69% 88.68% 89.46% 90.08% 90.61% 91.05% 91.44%

m*

m*/n

2.53012

84.34%

4.13216

82.64%

4.95299

82.55%

5.78412

82.63%

6.62399

82.80%

10 20 30 40 50 60 70 80 90 100

d

n

5

3 5 6 7 8 10 20 30 40

m1 = 8.32541, m 2 = 1.0, m3 = 14.0295 − 6.18497i, m 4 = 14.0295 + 6.18497i m1 = 17.1067, m 2 = 1.0, m3 = 24.3438 − 9.06484i, m 4 = 24.3438 + 9.06484i m1 = 26 .1434 , m 2 = 0.999998 , m 3 = 34 .5146 − 11 .3237 i , m 4 = 34 .5146 + 11 .3237 i m1 = 35 .3212 , m 2 = 1.0, m 3 = 44 .6237 − 13 .2399 i , m 4 = 44 .6237 + 13 .239 i m1 = 44.592, m2 = 0.999999, m3 = 54.7 − 14.9309i, m4 = 54.7 + 14.9309i m1 = 53.9299, m2 = 1.0, m3 = 64.7564 − 16.4597i, m4 = 64.7564 + 16.4597i

m1 = 63 .3193 , m2 = 0.999999 , m3 = 74 .8 − 17 .8648 i , m4 = 74 .8 + 17 .8648 i

m1 = 72.7497, m 2 = 1.0, m3 = 84.8346 − 19.1714i, m 4 = 84.8346 + 19.1714i m1 = 82.2138, m2 = 1.0, m3 = 94.8629 − 20.3975i, m4 = 94.8629 + 20.3975

m1 = 91.7063, m 2 = 1.0, m 3 = 104 .886 − 21.5561i, m 4 = 104 .886 + 21.5561i

m values m1 = 2.58363, m 2 = 0.999997, m3 = 5.88364 + 1.74027i, m 4 = 5.88364 − 1.74027i m1 = 4.20868, m 2 = 0.999996, m3 = 7.91895 + 2.26682i, m 4 = 7.91895 − 2.26682i m1 = 5.03702, m 2 = 1.0, m3 = 8.933 + 2.49445i, m 4 = 8.933 − 2.49445i m1 = 5.87417 , m 2 = 0.999999, m 3 = 9.94516 + 2.70547 i, m 4 = 9.94516 − 2.70547 i m1 = 6.71901, m 2 = 1.0, m 3 = 10.9558 + 2.90304i, m 4 = 10.9558 − 2.90304i m1 = 8.42815, m 2 = 1.0, m 3 = 12.9734 + 3.26621i, m 4 = 12.9734 − 3.26621i m1 = 17 .2292 , m 2 = 0.999999 , m 3 = 23 .0228 + 4.70244 i, m 4 = 23 .0228 − 4.70344 i m1 = 26.2747, m 2 = 1.0, m3 = 33.0458 + 5.80922i, m 4 = 33.0458 − 5.80922i m1 = 35.4581, m 2 = 0.999999 , m 3 = 43.0591 + 6.7407 i, m 4 = 43.0591 − 6.7407 i, m 5 = 40.9967

- 49 -

8.32541

83.25%

17.1067

85.53%

26.1434

87.14%

35.3212

88.30%

44.592

89.18%

53.9299

89.88%

63.3193

90.46%

72.7497

90.94%

82.2138

91.35%

91.7063

91.71%

m*

m*/n

2.58363

86.12%

4.20868

84.17%

5.03702

83.95%

5.87417

83.92%

6.71901

83.99%

8.42815

84.28%

17.2292

86.15%

26.2747

87.58%

35.4581

88.65%

50 60 70 80 90 100

d

n

1000

3 5 6 7 8 10 20 30 40 50 60 70

m1 = 44.7324, m 2 = 0.999996, m3 = 53.0677 + 7.56002i, m 4 = 53.0677 − 7.56002i, m 5 = 53.0677 − 7.56002i m1 = 54.0729, m 2 = 0.999997, m3 = 63.0739 + 8.29985i, m 4 = 63.0739 − 8.29985i, m5 = 60.9967 m1 = 63.4642, m 2 = 1.0, m3 = 73.0784 + 8.97951i, m 4 = 73.0784 − 8.97951i, m5 = 70.9967 m1 = 72.8962, m 2 = 0.999999, m3 = 83.0819 + 9.61155i, m 4 = 83.0819 − 9.61155i, m5 = 80.9967 m1 = 82 .3617 , m 2 = 1.0, m 3 = 93 .0847 + 10 .2048 i, m 4 = 93 .0847 − 10 .2048 i, m 5 = 90 .9967 m1 = 91 .8553 , m 2 = 1.0, m 3 = 103 .087 + 10 .7655 i, m 4 = 103 .087 − 10 .7655 i, m 5 = 100 .997

m values m1 = 2.58967 , m 2 = 1.00001, m 3 = 5.83508 + 1.61495 i, m 4 = 5.83508 − 1.61485 i, m 5 = 4.00002 , m 6 = 5.99999 m1 = 4.21737 , m 2 = 1.0, m 3 = 7.86148 + 2.10706 i , m 4 = 7.86148 − 2.10706 i, m 5 = 6.0001, m 6 = 7 .99999 m1 = 5.04664, m 2 = 0.999998, m 3 = 8.87218 + 2.31933i, m 4 = 8.87218 − 2.31933i, m 5 = 6.99987 m1 = 5.88446 , m 2 = 0.999999 , m 3 = 9.88154 + 2.51586 i, m 4 = 9.88154 − 2.51586 i, m 5 = 13 m1 = 6.72985, m 2 = 1.0, m3 = 10.8897 + 2.69969i, m 4 = 10.8897 − 2.69969i, m1 = 8.4399 , m 2 = 0.999998 , m 3 = 12 .9033 + 3.0373 i , m 4 = 12 .9033 − 3.0373 i , m 5 = 13 m1 = 17.2431, m 2 = 0.999998 , m 3 = 22.9416 + 4.3708i, m 4 = 22.9416 − 4.3708i, m 5 = 21.0004 , m 6 = 23 m1 = 26 .2896 , m 2 = 1.0, m 3 = 32 .9592 + 5.39554 i, m 4 = 32 .9592 − 5.39554 i, m 5 = 31 .0004 , m 6 = 33 m1 = 35 .4735 , m 2 = 1.0, m 3 = 42 .9693 + 6.25843 i, m 4 = 42 .9693 − 6.25843 i, m 5 = 40 .9983 m1 = 44.7479, m 2 = 0.999997 , m 3 = 52.976 + 7.01711i, m 4 = 52.976 − 7.01711i, m 5 = 51.0021, m 6 = 53 m1 = 54.0884, m 2 = 0.999998, m3 = 62.9808 + 7.70215i, m 4 = 62.9808 − 7.70215i, m5 = 61.0068, m 6 = 63 m1 = 63 .4797 , m 2 = 1.0, m 3 = 72 .9843 + 8.33145 i, m 4 = 72 .9843 − 8.33145 i, m 5 = 71 .0123, m 6 = 73

- 50 -

44.7324

89.46%

54.0729

90.12%

63.4642

90.66%

72.8962

91.12%

82.3617

91.51%

91.8553

91.86%

m*

m*/n

2.58967

86.32%

4.21737

84.35%

5.04664

84.11%

5.88446

84.06%

6.72985

84.12%

8.4399

84.40%

17.2431

86.22%

26.2896

87.63%

35.4735

88.68%

44.7479

89.50%

54.0884

90.15%

63.4797

90.69%

m1 = 72 .9133 , m 2 = 1 .0, m 3 = 82 .9866 + 8 .91828 i ,

80

m 4 = 82 .9866 − 8 .91828 i , m 5 = 83 + 2 .54662 × 10 − 6 i , m 6 = 83 − 2 .54662 × 10

−6

72.9133

91.14%

82.3782

91.53%

91.872

91.87%

i

m1 = 82 .3782 , m 2 = 1 .0, m 3 = 92 .9888 + 9 .4672 i ,

90

m 4 = 92 .9888 − 9 .4672 i , m 5 = 92 .9999 − 3 .02059 × 10 − 5 i , m 6 = 93

m1 = 91 .872 , m 2 = 1.0, m 3 = 102 .991 + 9.98668 i,

100

m 4 = 102 .991 − 9.98668 i, m 5 = 103 + 5.08397 × 10 − 5 i, m 6 = 103

- 51 -

BIBLIOGRAPHY

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Levin, D. (1990) “Horizontal mergers: The 50-percent benchmark.” The American Economic Review 80(5), pp. 1238-1245.

Mankiw, G. and Whinston, M. (1986) “Free Entry and Social Inefficiency.” The RAND Journal of Economics, Vol. 17, No. 1, pp. 48-58.

Perry, M. and Porter, R. (1985) “Oligopoly and the Incentive for Horizontal Merger” The American Economic Review, Vol. 75, No. 1, pp. 219-227.

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